Extension notifications - don't send email if to address blank

app/mailers/extension_mailer.rb

@@ -14,7 +14,7 @@ def follower_notification_email(extension_version, user)
     @email_preference = user.email_preference_for('New extension version')
     @to = user.email
 
-    mail(to: @to, subject: "A new version of the #{@extension_version.name} #{I18n.t('nouns.extension')} has been released")
+    mail(to: @to, subject: "A new version of the #{@extension_version.name} #{I18n.t('nouns.extension')} has been released") unless @to.blank?
   end
 
   #
@@ -29,7 +29,7 @@ def extension_deleted_email(name, user)
     @email_preference = user.email_preference_for('Extension deleted')
     @to = user.email
 
-    mail(to: @to, subject: "The #{name} #{I18n.t('nouns.extension')} has been deleted")
+    mail(to: @to, subject: "The #{name} #{I18n.t('nouns.extension')} has been deleted") unless @to.blank?
   end
 
   #
@@ -52,7 +52,7 @@ def extension_deprecated_email(extension, replacement_extension, user)
       of the #{@replacement_extension.name} #{I18n.t('nouns.extension')}
     ).squish
 
-    mail(to: @to, subject: subject)
+    mail(to: @to, subject: subject) unless @to.blank?
   end
 
   #
@@ -89,7 +89,7 @@ def notify_moderator_of_new(extension_id, user_id)
 
     @subject = %(New #{I18n.t('nouns.extension')} "#{@extension.name}" has been added to the Bonsai Asset Index)
 
-    mail(to: @moderator.email, subject: @subject)
+    mail(to: @moderator.email, subject: @subject) unless @moderator.email.blank?
   end
 
   #
@@ -107,6 +107,6 @@ def notify_moderator_of_reported(extension_id, user_id, report_description, repo
 
     @subject = %(#{I18n.t('nouns.extension').capitalize} "#{@extension.name}" reported)
 
-    mail(to: @moderator.email, subject: @subject)
+    mail(to: @moderator.email, subject: @subject) unless @moderator.email.blank?
   end
 end